Silicone-polyether block copolymers with high molecular weight polyether residues and their use as stabilizers for production of polyurethane foams

Abstract

Silicone-polyether block copolymer comprising a polyorganosiloxane which includes at least one polyether residue having a molecular weight of not less than 5000 g/mol, and wherein a weight average molecular weight of all polyether residues attached to the polyorganosiloxane by a chemical bond is above 3000 g/mol, its production and use and also compositions and polymeric articles obtained therewith.

1 . A silicone-polyether block copolymer comprising a polyorganosiloxane comprising at least one polyether residue having a weight average molecular weight of not less than 5000 g/mol, and wherein a weight average molecular weight of all polyether residues attached to the polyorganosiloxane by a chemical bond is above 3000 g/mol. 
     
     
         2 . The silicone-polyether block copolymer according to  claim 1 , wherein said at least one polyether residue having a weight average molecular weight of not less than 5000 g/mol and at least one other polyether residue having a weight average molecular weight of below 5000 g/mol are attached to the polyorganosiloxane by a chemical bond. 
     
     
         3 . The silicone-polyether block copolymer according to  claim 1 , wherein the weight average molecular weight of all polyether residues attached to the polyorganosiloxane by the chemical bond is above 3000 g/mol and below 5000 g/mol. 
     
     
         4 . The silicone-polyether block copolymer according to  claim 1 , wherein said silicone-polyether block copolymer is of a structure of formula (I) 
       
         
           
           
               
               
           
         
       
       where
 n and n 1  are each independently from 0 to 500 and (n+n 1 ) is <500, 
 m and m 1  are each independently from 0 to 60 and (m+m 1 ) is <60, 
 k is from 0 to 50, 
 R represents alike or unalike radicals selected from the group consisting of linear, cyclic or branched, aliphatic or aromatic, saturated or unsaturated hydrocarbon radicals having from 1 up to 20 carbon atoms, 
 
       
         
           
           
               
               
           
         
         
           where 
           x′ is 0 or 1 and 
           R IV  is an optionally substituted, optionally halogen-substituted hydrocarbon radical having 1 to 50 carbon atoms, 
         
         R 1  is R or R 3 , 
         R 2  is R or R 3  or a heteroatom-substituted, functional, organic, saturated or unsaturated radical, 
         R 3  is -Q-O—(CH 2 —CH 2 O—) x —(CH 2 —CH(R′)O—) y —(SO) z —R″
 or 
 -Q-O—(CH 2 —CH 2 O—) x —(CH 2 —CH(R′)O—) y —R″, 
 where 
 Q=divalent hydrocarbon radical having 2 to 4 carbon atoms, x=0 to 200, 
 y=0 to 200, 
 z=0 to 100, 
 R′ is an alkyl or aryl group which has 1 to 12 carbon atoms and is unsubstituted or optionally substituted, and 
 R″ is a hydrogen radical or an alkyl group having 1 to 4 carbon atoms, a —C(O)—R′″ group where R′″=alkyl, a —CH 2 —O—R′ group, an alkylaryl group, or a —C(O)NH—R′ group, 
 SO is a styrene oxide radical —CH(C 6 H 5 )—CH 2 —O—, 
 
         with the proviso that at least one radical is an R 3  radical and that at least one R 3  radical is a polyether residue having a weight average molecular weight not less than 5000 g/mol and the weight average molecular weight of all polyether residues R 3  in the copolymer of formula (I) is more than 3000 g/mol, and n+n 1 +m+m 1  is not less than 15. 
       
     
     
         5 . The silicone-polyether copolymer according to  claim 4 , wherein R″ is hydrogen for all polyether residues R 3  having a weight average molecular weight not less than 5000 g/mol. 
     
     
         6 . The silicone-polyether copolymer according to  claim 4  wherein R″ is other than hydrogen for all polyether residues R 3  having a weight average molecular weight below 5000 g/mol. 
     
     
         7 . A process for production of a silicone-polyether block copolymer comprising: reacting a branched or linear polyorganosiloxane having terminal and/or lateral SiH functions with a polyether or polyether mixture of two or more polyethers, wherein the polyether used or the polyether mixture used includes at least one polyether having a molecular weight not less than 5000 g/mol and an average molecular weight of all polyethers used is above 3000 g/mol. 
     
     
         8 . A composition comprising the silicon-polyether copolymer according to  claim 1  and one or more substances useful in polyurethane foam production and selected from nucleating agents, cell-refining additives, cell openers, crosslinkers, chain extenders, emulsifiers, flame retardants, antioxidants, UV stabilizers, antistats, biocides, color pastes, solid fillers, amine catalysts, metal catalysts and buffer substances. 
     
     
         9 . The composition according to  claim 8 , further comprising one or more solvents. 
     
     
         10 . A method for the production of a polyurethane foam comprising: reacting a silicone-polyether block copolymer with at least a polyol and a diisocyanate, wherein said silicone-polyether block copolymer comprises a polyorganosiloxane comprising at least one polyether residue having a weight average molecular weight of not less than 5000 g/mol, and wherein a weight average molecular weight of all polyether residues attached to the polyorganosiloxane by a chemical bond is above 3000 g/mol. 
     
     
         11 . The method according to  claim 10 , wherein the silicone-polyether block copolymer is used as a foam stabilizer. 
     
     
         12 . The method according to  claim 10 , further comprising a blowing agent selected from the group consisting of water, methylene chloride, pentane, alkane, halogenated alkane, acetone and carbon dioxide.